intravascular catheter includes a nested portion including an inner and outer tubular catheter member fitted, the sheath having a proximal end which is supported on one end of the inner and outer catheter members, through the sheath moveable proximally and distally, having an elongated flexible drive member which is coaxially disposed inside. Drive member has a distal portion that is accommodated in the sheath, and a second non-covered portion of which extends beyond the sheath within the telescopic portion. Uncoated portions of the drive member is greater than the coating disposed distal portion of the drive member, and has a stiffness sufficiently large to self-supporting non-covered portion of the drive portion is in the nested position.血管内カテーテルは、嵌め込まれた内側及び外側管状カテーテル部材を含む入れ子箇所と、内側及び外側カテーテル部材の一つの端部に支持される近位端を有するシースと、前記シースを通って近位側及び遠位側に移動可能で、その内側に同軸配置される細長い柔軟なドライブ部材とを有する。ドライブ部材は、シース内に収納される遠位部分と、入れ子箇所の内部でシースを超えて延びる第二の非被覆部分とを有する。ドライブ部材の非被覆部分は、ドライブ部材の被覆配置された遠位部分より大きく、かつ、ドライブ部分の非被覆部分が入れ子箇所内で自己支持するに十分な大きさの剛性を有する。
